Zoom lens system

A zoom lens system, in this order from an object side to an image side thereof, comprising:

• a first lens group of negative refractive power, the first lens group comprising, in this order from the object side to the image side of the zoom lens system, a first lens of negative refractive power and a second lens of positive refractive power;
• a second lens group of positive refractive power, the second lens group being capable of floating to realize an image stabilization function and comprising, in this order from the object side to the image side of the zoom lens system, a third lens of positive refractive power, a fourth lens of positive refractive power, a fifth lens of negative refractive power, and a sixth lens of positive refractive power;
• and
• a third lens group of positive refractive power, the third lens group comprising a seventh lens of positive refractive power;
• wherein the zoom lens system satisfies the following condition formula:
• 0.3<d2a/D2<0.4, where d2a is a length of the optical axis of the zoom lens system between an image-side surface of the fifth lens and an image-side surface of the sixth lens, and D2 is a length of an orthogonal projection of a connection line on the optical axis of the zoom lens system, the connection line connects between a point of the second lens group closest to the object side of the zoom lens system and a point of the second lens group closest to the image side of the zoom lens system.